All the known methods and devices of this type have limits, with regards to application and effectiveness.
Ideally, a contraceptive means must have a 100% efficiency, but enable unimpeded sexual intercourse, be comfortable to wear, inexpensive and in particular being removable to reverse the contraceptive effect.
Already, numerous contraceptive means are known, e.g. devices which are inserted into the vagina, condoms and the like, but these are not completely effective. Devices which are inserted into the uterus, such as IUD's have the disadvantage of causing bleeding and pain, as a result of contact in the uterus with the discharges thereof. This makes regular replacement necessary in order to physically modify the surfaces and also adapt to chemical menstruation. Contraceptive pills on a hormone base lead to the known side-effects. Sterilization by ligation of the uterine tube, resection, rings or clamps, leading to irregularity in the funnel-shaped ectasias, are also disadvantageous. Thus, these methods require surgery and it is difficult, if not impossible, to restore receptivity for normal reproduction.
Finally, means exist for closing the trumpet-shaped ectasias by injection using a hysteroscope, using a mixture of a liquid preelastomer and a catalyst injected for polymerizing the material in the uterine tube. However, this requires a special technique with a local anesthetic, requiring a pumping device for injection. There is also a possibility of failure and the increased risks, due more particularly to the instability of the injection material. Reversibility through the use of hysteroscopy is theoretically possible, but the passage of the distal outer end of the syringe having a diameter of several millimeters can injure the isthmian canal of the trumpet-shaped ectasia with a diameter below 1 mm, despite the elasticity of the elastomer.